Free Alkyl Halides MCQs with Answers
458 Alkyl Halides MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Alkyl halides are named and related to their carbon-halogen structure, polarity and reactivity. The key reactions are nucleophilic substitution by SN1 and SN2 mechanisms and elimination by E1 and E2 mechanisms, including how substrate structure, nucleophile, base, solvent and temperature influence substitution versus elimination.
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Read the Alkyl Halides notesFree MDCAT chapter notes with key terms458 questions · page 9 of 23
161. The reaction in which a molecule is removed from a compound but no addition takes place is called _?
- A. Substitution reaction
- B. Elimination reaction
- C. Addition reaction
- D. Replacement reaction
Explanation: An elimination reaction is a type of organic reaction in which two substituents are removed from a molecule in either a one-step or…
Correct answer: Elimination reaction- A. E1,SN2
- B. E2,SN1
- C. E2,SN2
- D. E1,S1
Explanation: Both E1 and SN1 start the same way, with the dissociation of a leaving group, forming a trigonal planar molecule with a carbocation.
Correct answer: E1,S1- A. 1-chloropropane
- B. 2-chloropropane
- C. n-butyl chloride
- D. 2-methyl,2-chloropropane
Explanation: 2-methyl,2-chloropropane is correct as we know that SN1 reactions are given by tertiary alkyl halides and option D is a tertiary alkyl…
Correct answer: 2-methyl,2-chloropropane- A. Substituents
- B. Parent name
- C. Ligand
- D. Longest chain
Explanation: Option A is correct as it is written in PTB that haloalkanes are halogen derivatives of alkanes.
Correct answer: Substituents- A. From opposite side of leaving group
- B. From front of leaving group
- C. From both sides
- D. None of these
Explanation: Is correct as in SN1 mechanism , the nucleophile can attack from both front and opposite sides of the leaving group .
Correct answer: From both sides- A. Dehydration
- B. Protonation
- C. Ionization
- D. Attack of nucleophile and departure of leaving group
Explanation: Ionization is correct as in SN1 reaction a carbocation is formed in the first step the tertiary alcohol is ionized.
Correct answer: Ionization- A. Alkyl bromide
- B. Alkyl fluoride
- C. Alkyl chloride
- D. Alkyl iodide
Explanation: Grignard reagent is formed by the reaction of alkyl halide or aryl halide with Mg.
Correct answer: Alkyl iodide- A. Inversion in configuration
- B. Retention in configuration
- C. 50% retention in configuration
- D. 50% inversion in configuration
Explanation: The question deals with knowing the mechanism of SN2 reaction and evaluating the inversion of the end product in relation to the initial…
Correct answer: Inversion in configuration- A. Substrate only
- B. Nucleophile
- C. Substrate and nucleophile
- D. All of these
Explanation: Reason: In SN2 reactions, the reaction is first order in the substrate and the nucleophile.
Correct answer: Substrate and nucleophile- A. CH3-CH2-CH(CI)-CH(CH3)
- B. CH3-CH2-CH(CH3)-CH(CI)-CH3
- C. CH3-CH2-CH(CI)-CH(CI)-CH3
- D. CH3-CH2-CH(CI)-CH(CH3)-CH3
Explanation: Reason: Has a chlorine group on second carbon and methyl group on third carbon. Longest chain is 5 carbons.
Correct answer: CH3-CH2-CH(CH3)-CH(CI)-CH3- A. Leaving group
- B. Electrophile
- C. Substrate
- D. Weak nucleophile
Explanation: Option A is correct as groups or particles that leave the main by being substituted are called "leaving groups".Option B is incorrect as…
Correct answer: Leaving group- A. Transition state
- B. Intermediate
- C. Carbocation
- D. Carbanion
Explanation: Option A is correct as SN2 reactions are one step reactions that have a "transition state" in the reaction process.
Correct answer: Transition state- A. Electrophile
- B. Lewis acid
- C. Nucleophile
- D. Strong acid
Explanation: Option C is correct as H3O+ is a positively charged molecule and "nucleophiles" are negative molecule which are attracted to positively…
Correct answer: Nucleophile- A. SN1, E1
- B. SN2, E1
- C. SN2, E2
- D. None of these
Explanation: Option CSN2, is a Bimolecular nucleophilic substitution reaction , occurs in one stepE2, Bimolecular one step Elimination ReactionThus…
Correct answer: SN2, E2- A. Electrophile
- B. Lewis acid
- C. Nucleophile
- D. Strong acid
Explanation: Option C is correct since H3O+ has a lone pair of electrons, but due to the presence of a positive charge, it can't donate its electron…
Correct answer: Nucleophile- A. Substituents.
- B. Parent name.
- C. Ligand.
- D. Longest chain.
Explanation: Halogens are named as substituents in the nomenclature of alkyl halides.
Correct answer: Substituents.- A. Electrophilic carbon.
- B. Nucelophilic carbon.
- C. Beta-hydrogen.
- D. None of these.
Explanation: The base attacks the beta hydrogen atom instead of the carbon atom that is attached to the halogen.
Correct answer: Beta-hydrogen.- A. 1st order
- B. zero order
- C. 2nd order
- D. 3rd order
Explanation: Option C is correct since the SN2( nucleophilic substitution) reaction follows second-order kinetics; that is, the rate of the reaction…
Correct answer: 2nd order- A. Presence of Mg atom
- B. Polarity of C-H bond
- C. Polarity of C-Mg bond
- D. Presence of electrophilic carbon
Explanation: Option C is correct since the reason for the reactivity of the 'Grignard reagent' is the polarity of the C-Mg bond.
Correct answer: Polarity of C-Mg bond- A. 1st order reaction
- B. 2nd order reaction
- C. Zero order reaction
- D. 3rd order reaction
Explanation: According to kinetic evidence , the rate of reaction is directly proportional to substrate and base.
Correct answer: 2nd order reaction